Field of the Invention
The present invention relates to a turning controller.
Discussion of the Background
It is well known that a workpiece is held on a spindle of a lathe and is thus rotated, and a tool is fed in a longitudinal direction of the workpiece (a Z-axis direction) to carry out turning work with a cutting edge of the tool cut in a predetermined cutting depth in a radial direction (an X-axis direction) of the workpiece. When the turning work is performed, a principal force, a feed force, and a thrust force are applied to the tool. The thrust force is a component in a radial direction (an X-axis direction) of a cutting resistance of the workpiece, and applies a force so as to bend the workpiece in the radial direction (the X-axis direction) of the workpiece. For this reason, when a fine shaft having a high aspect ratio is subjected to turning work, it is impossible to ignore influence on turning accuracy by the thrust force.
Therefore, it is conventionally proposed that a tool capable of setting the thrust force to zero should be designed as disclosed in Japanese Unexamined Patent Application Publication No. 2009-113143, for example. Specifically, Japanese Unexamined Patent Application Publication No. 2009-113143 describes designing a tool including an approach angle for causing a thrust force to be zero when a certain cutting depth is set based on knowledge that a single approach angle for causing the thrust force to be zero is defined depending on the cutting depth.